I would have to go with Manak's behavior as the most revealing in Pritam's short story. I believe that his speech and behavior reflect the oppressive nature of traditional social modes. Manak is shown as someone who is constantly trying to fight the overarching condition of totality in way of the tradition and social honor that surround him.
How he pleads with Guleri not to leave, and is then rebuffed by her is one example of this. Another example is seen when he returns home to his mother. She is more than eager to replace Guleri with a new wife who will be able to bear Manak's children, and she rebukes Manak for his sadness in the process. These are both moments where his impotence against the traditional social structure is evident.
Manak's emptiness and vacant stares (when Bhavani tells him that Guleri has committed self- immolation upon learning of Manak's second wife) display another element of how Manak is powerless to stop the train and "progress" of modernity. At the same time, I think that his rejection of the child, in the end, is a small moment where he actually speaks out against tradition, something that will become silenced in due time.
I don't think that Manak is the saddest character or the one most deserving of empathy or sympathy. That has to be Guleri, who leaves her husband thinking all is well, but ends up having to set fire to herself out of shame for being unable to bear children. Yet, I think that Pritam constructs the character of Manak in such a way that he is shown to be an individual who detests the social and traditional structure in which he lives, but one who lacks the full throated control to reject it and leave it.
Perhaps, his actions at the end are the start of a process that already claimed two casualties in Manak's love and Guleri, herself. It is in this where I think that his characterization is the most revealing in the emptiness of an individual who dislikes tradition, but remains a part of it.